Quick-break switch



(No Model.)

H. P. DAVIS. QUICK BREAK SWITCH.

Patented Mar. 1, 1898.

@ZZZESSES;

TTOFPNEY.

m: mums mins co, PNDTO-LIINLL. wAsnmmon. D. c.

I UNrTEn STATES PATENT QFFICE.

HARRY P. DAVIS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE WESTINGHOUSEELECTRIC AND MANUFACTURING COMPANY, OF

ENNSYLVANIA.

SPECIFICATION forming part of Letters Patent No. 599,929, dated March 1,1898.

Application filed July 22,1 89 7- To all whom it may concern:

Be it known that I, HARRY P. DAVIS, a citizen of the United States,residing in Pittsburg, in the county of Allegheny and State ofPennsylvania,have invented a new and useful Improvement in Quick-BreakSwitches, of which the following is a specification.

My invention relates to switches for electric circuits, and particularlyto devices of this general class which are known as quickbreak switches.

The object of my invention is to provide a switch which shall have alarge current-carrying capacity in proportion to the dimensions of thedevice and which shall be simple and inexpensive in construction andcertain in operation.

In the accompanying drawings, Figure 1 is a view, partially in sideelevation and partially in section v of a switch constructed inaccordance with my invention; and Fig. 2 is a front elevation of thesame. Fig. 3 isa detail view, partially in plan and partially insection.

The details of construction are as follows:

1 is the usual switchboard-base, of marble or other insulating material,and 2 and 2 are stationary jaw-terminals mounted upon the base 1 andhaving terminal studs 3, extending through such base to the rear.

4 is the switch-blade, provided with two pairs of spring-washers 5.These washers are preferably provided with radial slits extending inwardsome distance from their edges and are riveted to the sides of theblade, so as to be slightly concave or dish-shaped. One pair are locatedpermanently in the jaw-terminal 2,the blade-pivot'passin g through theircenters. The other pair of washers are fastened to opposite faces of theblade or near the other end in the same manner and in such a position asto engage with the inner faces of the jaw-terminal 2 when the switch isclosed.

The jaw-terminal 2 has electrically connected to it, and preferablymechanically also, two spring-arms 14, which project substantiallyparallel to each other and somewhat beyond the outer ends of the jaw-terminal. The outer ends of these spring-arms are curved inwardtoward each other, as clearly shown in Fig. 3 at 15, or they may beotherwise pro- Se'rlal No. 645,491. (No model.)

vided with projections which are nearer together than the inner sides ofthe main portions of the arms.

The blade is provided at the end last referred to with the usual handle6. At a suitable point intermediate the two pairs of washers andpreferably somewhat nearer the pivoted end are riveted supporting andguiding plates 7. A tongue 8 is pivoted at one end between the plates 7and extends along the inner edge of the blade 4 and substantiallyincontact therewith when the switch is closed. This blade 8 is providedwith two curved strips 9, which extend outward and fit against the twofaces of the blade 4. Their inner edges also fit against thecorrespondinglycurved outer edges of the plates 7, the curva ture ofboth these engaging edges of the parts 7 and 9 being that of an arc of acircle struck from the pivot of the tongue 8 as a center. The plates 7are also provided with projections 10, which constitute stops, as willappear from the description of the operation of the device. The innerends of the guide strips or pieces 9 are provided with alaterally-extending bar 11, to the ends of which are connected the innerends of coiled springs 12, the outer ends of these springs beingfastened to a pin 13, extending through the blade 4.

The free end of the tongue 8 is provided with a laterally-projectinghead 16, the ends of which are normally in contact, or substantially so,with the inner faces of the arms 14.

The structure of the spring-tongue and of the cooperating supplementalcontact piece or pieces maybe varied materially from what is shownwithout departing from the invention. For example, either or both ofthese devices may be designed to yield with reference to the other inorder thata quick break of the circuit may be effected.

The operation of the switch is as follows: When the switch-blade ismoved outward by means of its handle 6, the tongue 8 will follow themovement of the blade more or less closely, depending upon the degree offrictional contact bet-ween the ends of the head 16 and the inner faces14 until such head comes in contact with the inwardly-projectingportions 15,when its movement will be stopped until the blade reachesthe position indicated in broken lines in Fig. 1, when the bar 11 willcome into contact with the stops 10, the head 16 being thus caused toforce the projections 15 away from each other. As soon as it has passedthese projections the springs 12 will draw the tongue 8 quickly into itsnormal position in contact, or substantially so, with the edge of theblade 4. Inasmuch as the head 16 remains in contact with the plates 14until the washers 3 have become entirely separated from thecorresponding jaw-terminal, the current will be shunted through thetongue and the plates 14 and quicklyinterrupted when those parts areseparated. Particularly good contact is eifected between the tongue 8and the blade 4by means of the curved arms 9, and the main contacts ofthe switch also provide large carrying capacity by reason of the splitspringwashers, which yield sufficiently to make an intimate engagementbetween their outer faces and the inner faces of the jaw-terminals.

\Vhile I have illustrated and described specific details ofconstruction, I desire to be understood that these details may be variedto a considerable degree without departing from the spirit and scope ofthe invention.

I claim as my invention 1. A quick-break switch for electric circuitscomprising two stationary jaw-terminals and an auxiliary jaw'terminalhaving laterallyyielding, resilient sides, in combination with a bladeprovided with a tongue having a head at its free end for engagement withthe auxiliary jaw-terminal.

2. A quick-break switch comprising a pair of stationary jaw-terminalsand a pair of spring plates or strips the space between which iscontracted at or near their outer ends, in combination with a bladehaving a tongue extending along its inner edge and provided with a headat its free end which engages with the inner faces of the spring platesor strips.

3. A quick-break switch comprising a pair of stationary jaw-terminalsand a pair of spring-plateselectrically connected with one of saidterminals and projecting inwardly toward each other at or near theirfree ends in combination with a blade, a pivoted tongue extending alongthe inner edge of said blade and having a head at its free end forengagement with the inner faces of the spring-plates, a springconnecting said blade and said tongue and a combined support,contact-maker and stop, the members of which are rigidly connected tosaid blade and said tongue respectively.

4. A quick-break switch comprising a pair of stationary jaw-terminalsand an auxiliary spring-terminal electrically connected with one of saidjaw-terminals, in combination with a blade, a tongue connected at oneend to said blade and having a head at its other end engaging with saidspring-terminal and a spring connection between said blade and saidtongue.

5. A quick-break switch comprising a pair of stationary jaw-terminalsone of which is provided with a pair of spring contact plates or strips,in combination with a blade,a tongue pivotally attached to the loweredge of said blade and having a head engaging with the inner faces ofsaid plates or strips and arms engaging the faces of said blade, andsprings between said tongue and said blade.

6. A quick-break switch comprising a pair of stationary jaw-terminalsand an auxiliary spring-terminal electrically connected with one of saidjaw-terminals, in combination with a blade provided with spring-washersriveted to its sides, a tongue connected at one end to said blade andhaving a head at its other end engaging with said spring-terminal and aspring connection between said blade and said tongue.

7. A quick-break switch for electric circuits comprising two stationaryj aw-terminals and an auxiliary jaw-terminal having laterallyyielding,resilient sides, in combination with a blade provided withspring-washers for engagement with the main jaws, and a tongue having ahead at its free end for engagement with the auxiliary jaw-terminal.

In testimony whereof I have hereunto subscribed my name this 20th day ofJuly, A. D. 1897.

HARRY P. DAVIS.

Witnesses:

WESLEY G. CARR, H. G. TENER.

